Vacuum steam heating system



Jan. 31, 1933- NASH VACUUM'STEAM HEATING SYSTEM Filed May 7, 1928 2Shets-Sheet 1 INVENTOR flazfgias .E'jNzeZu,

BY I

ATTORNEY-5' Jan. 3 1933. D E. NASH VACUUM STEAM HEATING SYSTEM Filed May7, 1928 2 Sheets-Sheet /////A I I I I I: I

I N V EN TOR flazpjlaa E M70,

Patented Jan. 31, 19 33 UNITED STATES.

DOUGLAS E. NASH, or some; NORWALK, connnc'rreor, AssIGnon To manager-NEERING- COMPANY, OF CONNECTICUT VACUUM STEAM HEATING SYSTEMApplicationfiled May 7, 1928. Serial K0, 275,523. V Under either ofthese conditions, the are In vacuum steam heating, as practiced to day,-a pumping apparatus is employed which keeps the return side of thesystem under a partial vacuum, and forces the water of con densationback to the boiler. An improved form of such apparatus is shown inpatent granted to Irving G. Jennings, dated December 29, 1925, No.1,567,148.

The specific apparatusshown in this patent comprises a receivingandseparating tankinto which the returns from the steam heating system areled, an electric motor driving a well known Nash hydro-turbinepumpcovered by Patent No. 953,222, dated March 29th, 1910, which acts toexhaust the air or' gas from said receiving tank, and a rotary orcentrifugal water Wheel, Which acts to remove the water of condensationfrom the re ceiving or separating tank and force'the same back to theboiler. p 1

While my invention has been'designed for use in connection with anyapproved form of vacuum steam heating apparatus, it is specificallyshownand described in'this application for patent as'connected and usedin said system in which the said Nash pump is emp1oyed.-- a p Itfrequently happens that's'ome or all of the return lines come back tothe boiler room, in which the pumping apparatus is placed, at a pointlower than it is practical to place the receiving or separating tank. Itis cuetomary to use lift fittings to raise the con densate from thislower'level up to the receiving tank. For this arrangement to'operate,it is necessary that a lower. pressure exist in the receiving tank thanin the low, point of the return line and this difference in pressuremust be enough to overcome the necessary lift.

When the vacuum in the receiving tank has been raised to a' high-point,either by the operation of the pumpor bycondensation in the heatingcoils or radiators overcoming the steam supplied to the system, the pumpmay be shut down by the vacuum control, if such control is used. Inothercases, the

maximum capacity of the pump may be" reached too early, due to leakytraps or to excessive air leaks into the system.

of my improved lift trap-Q ference in pressure-between the returnlinescorn NORWALK, oonnno'rrcu'r. A .conronnrron or and the receivingtankmay not be sufficient to raise the condensate from the low returnlinesup to the receiving tank, andthesystem may beput out ofoperatiom'the circulation stopped, and possibly'the boiler 'damaged.

The object of the presentinventionis to overcome these difficulties andmake vacuum steam heating eflicieiit-and perfect in operation, even ifit is necessary to'use return pipes extending at a lower level-than theseparat ing tank or receiver. a i

To accomplish this useful purpose, "I have invented an automaticallyoperating lift-tra which is interposed at'substantially the low point inthe return line. This lift trap works by means of a float controlledvalve, which automaticallyhlets the right amount of at Inosphericair orpressure into the'trap to blow or force the trapped condensate up intothe receiving tank. r V

The improved details of this'trap will be set forth in thisspecification. y a The invention is illustrated in the accom Figure 1 isa-diagram illustrating a vacuum steam heating system employing thepumplng apparatus of said, Patent No.

1,567,148, and illustrating how my improved and Fig. 2 is a crosselevation on a large scale 7-6 I panying two sheets of drawings, inwhich Referring to thedrawings imam detail,1'

designates the steam boiler, from which ex' tends the steam main 2, fromwhich branches,

suchas 3 and 4, are'jled to distribute-steam to the. radiation.throughout the building to be heated. I I

Two radiators are indicated in F igure, 1, radiator 5 representingradiation above the boiler, and. radiator .6 representing radiationbelow the boiler. -These radiators-are provided with traps at the exitends; The returns from. the radiators, are collected by suitable returnpipes and are led into a re- I tank 12; The water collecting in the botturn main 7, which passes along at a point below the steam boiler.

The return main 7 is provided with a for-: wardly opening checkvalve 8andis connected into the casing of'my improved lift trap 9, which is-interposed at I substantially- .the low point in the"returnline. Thecondensate passes from thelift trap Qithr'ough a discharge pipe 10 tothe strainer or re ceiving inlet ofgthe receiving-orseparating tom ofthe receiving tank 12 is forced by the centrifugal pump,' of the pumpingapparatus, throughfpipe 13 back-into the boiler 1, and the air or'gascollecting in the top of the receivingor separatingtank 1 is drawn'outby the hydro-turbine Nash pump and forced out: into; the atmospherethrougha pipe" The two pumps are'driven-by an electric motor 15,controlled by a, vacuum control 16 and a float econtrol 17 The vacuumcontrol maybe operated-byaipipe 160 connected-to thereturn main 7. Thissystem' and pumping apparat s s arranged so that; a suitable vacuumwill. be maintained in the top of the receiver or-separating tank, andhence the return side ofthe'heating system will be kept under thisvacuum; and sothat the water of condensation will be, pumped back intothe boiler; The; pumps will be auto- 'matically cut into and'o'ut ofoperation by the vacuum and float controls. 7

t-In order that there may never be ,a great-.

' ing line beingainterposed inzthis equalizing line, the purpose ofthischeck valve being to prevent the flow of air from'the return line tothereceiving tank. .1

V {A check valve180 1s incorporated-in the manifold of thepump (as shownin Figure 1?) to prevent the return of atmospheric air through/pipe 14into the receivingtank,

' and hence into the-return line. system.

1The supply sideand return sides ofthe system are further equalized by apipe 20 extending from the pipe18 over to one of the steam supply pipes,as. 8, whichpipe 20 has} a check valve 21 interposed. therein openingtowards thesupply side of, the system. The purpose of'jthis pipe is toequalize the pres- ;sure on the return side of the system with thestea'msupply sideof jthe system, when ever the pressure in the steamsupplyside of the system is lower than thepressure in the returnside. 'Thislatter condition may "oc-' cur when a high vacuumis created in thesupply side of the system by condensation of the steam infthe supplypipes and radia tors when the boiler is shut down:- If this occurs";vapor willflow from the return line through pipe 20 tog-the steam sideand. the

two sides will balance whereby there will be no danger of the water inthe boiler being reduced to a. dangerous level. The check valve 21preventsa discharge of steam or va-' por from the' supplysidetothereturn side offthe system.

The; details ,of'my lift trap will'now be de scribed. A small hollowcasing 22 is secured to the top of the trap and the same is connected byan air'pipe 23 over toithe air escape pipe 14; The discharge pipe 10extending from the trap is carried down-near the bottom thereof by anextension pipe 24, a

so as to trap the water therein. i A hollowvalveseat 25is threadedinto'the tank. ,A valve 26 cooperates withsaid seat, said valve beingvarranged on a stem 27, which has suitable wings or ,guides'28. A small27, and. a large float30 is fitted to slide loosely upand down on saidstem between the small float 29 and a stop'31 adjustably secured on saidstem. I

The small float 29 hasa lifting when submerged, slightly in excessofthe'combinedweight-'of'the valve, valve stem, and

the float itself. v v e The operation ,of thistrap 1S asfollows':Whenthe' trap is empty, the weight of the large float 30 and theatmospheric pressure on float 29 is securedv on the bottom of the stemthe valve 26 keeps the valve closed; .Asthe condensate collects in thetrap, the large float 80 will rise on the stem 27 vbut atmospheric vpressure on the valve 26 will keep the same on its seat andthesmall'float 29 submerged;

\Vhenthe large float strikes the stop 31,'its lifting capacity issufficient to open the valve 26 against the'atmospheric pressure. Whenthe valve 26 is opened,j atmospheric air will 3 rush into the trap,through pipes 14 and 23 and will force or blow the trapped condensateover into the receivingtank'12, the check valve 8 being closed by thepressureof the entering air. As the condensate is blown. out, the largeHeat 30 will descend on the stem 27 until it strikes on the sma'llfloat29, and will then close the valve26. If the valve 26 is closed beforeallof the water. has been blown out of the trap, the expansive. force ofthe air 15 Y which hasfentered the-trap willconti'nue the operation,until all of the;w ater has, been blownover and until the major part ofthe entering air has also passedover into'the receivingtank 12 by reasonof=the vacuum therein. I

this air whichthus p asses'over mm the receiving tank 12 lowers thevacuum therein below that previously-established inv the return line 7,part of the 'airiwill flowfrom the.

receiving tank 12 through the pipe 18, and Y check valve '19,. into thereturn line 7 thus putting the receivingtank 12 in balance with thereturn line 7. This balance will 1 then allow the condensate to'flowagain into the trap 9.

If there should be any back Wash of water in the pipe 10 and extension24, or if there should be a little extra air caught in the trap 9, thehydro-static head of the water accumulating in the pipe 7 above thecheck valve 8 will overcome the same and will allow the condensate toflowinto the trap.

Thus provision is made for a positive and automatic lift of the water ofcondensation from the low return mains up into the re ceiving tank ofthe pumping apparatus. The difiicultiesbefore enumerated are'thusefficiently overcome. I

lVhile the lift trapflherein shown and described has been particularlydesigned for use in connection with vacuum steam heating systems, it canbe used in other locatlons where 1t is desired to lift a liquid overinto an evacuated tank, and the same is covered in detail by divisionalapplication for patent filed by me May 17th, 1930, Serial No. 453,270 inpursuance of a Patent Office requirement.

The details and arrangements herein shown and described may begreatlyvaried by a skilled mechanic Without departing from the scope of thepatent.

Having thus fully described my invention, what I desire to claim andsecure by Letters Patent is 1. A vacuum steam heating system comprisinga boiler, radiators, steam supply and return lines, a receiving andseparating tank for the condensate, a pumping apparatus for placing thereturn side of the system under a vacuum and returning the water of condensation to the boiler, said return line having a low point locatedbelow the level of said tank, and a lift trap interposed at the lowpoint in the return line, andvalve mechanism in the trap arranged toallow atmospheric air to flow into the trap to force the condensatereceived therein up into the receiving and separating tank when thecondensate has accumulated therein, and then to shut off the supply ofatmospheric air to allow a further accumulation of condensate therein.

2. A vacuum steam heating system comprising a boiler, radiators, steamsupply and return lines, a receiving and separating tank for thecondensate, a pumping apparatus for placing the return side of thesystem under a vacuum and returning the water of condensation to theboiler, said return linehaving a low point located below the level ofsaid tank, and a lift trap interposed at the low point in the returnline, a valve in the lift trap, and float mechanism for opening andclosing said valve to allow atmospheric air to flow into the trap toforce the condensate received therein up into the receiving andseparating tank when the condensate has accumulated therein, and then toshut off the supply of atmospheric air to allow a further accumulationof condensate therein. 7

' 3-, A vacuumsteam heating system com} a prising a boiler, radiators,steam supply and return lines, a receiving and separating tank for thecondensate, a pumping apparatus for placing the return side of thesystem'under a vacuum and returning the water of con densation to theboiler, saidreturn'line hav ing a low point located below the level ofsaid tank, and a lift trap interposedat the low point in the returnline, the'pipe extending from thetrap to the tank'being carried down inthe trap to near the bottom thereof: and

for the condensate, a pumping apparatus" for placing the return side ofthe system'under a vacuum, and said return line having a low 7 pointlocated below the level ofsaid tank, a lift trap interposed atsubstantially the low point in the return line, said lift traphavinga'valve for admitting airthereto, and

valve.

'95 dual float mechanism for operating said 5. A vacuum steamheatingsystem comprising a boiler,'ra diat0rs, steam supply andreturn'lines, a receiving and separating tank for the condensate, apumping apparatus for placing the return side of thesystem under avacuum, and said return line having a low point located below the levelof said tan'lnaa lift trap interposed at substantiallythe low point inthereturn line, said lifttrap having a valve for admitting airtheretoandtwo floats for operating said valve, the lifting capacity of onefloat and its connecting parts being: slightly in excess 1 of thecombined weight of the valve, the connecting parts and the float itself.a

6. A vacuum steam heatingsystemcom:

prising a boiler, radiators, steam supply and return lines, a receivingand separating tank vacuum, and said return line having a low pointlocated below the level ofsaid tank,a lift trap interposed atsubstantially the low point in the return line, said lift trap having-avalve for admitting air thereto, a valve stem ex tendingfrom said valve,afloat on the end for the condensate, a pumping apparatus for placingthe return side of the system under a thereof, a float loosely fitted onsaid stem, and

a stop with which said last named float coperates.

7. A vacuum steam heating system comprising a boiler, radiators, steamsupply and: return lines, a receiving and separating tank for thecondensate, a pump-ing apparatus for placing the returnside of thesystem under 7 1 a vacuum, and said return line having a low 7 pointlocated below the levelof said tank,,a lift .trapinterposed atsubstantially the low point inthe return line, said lift trap having avalve for admitting air thereto, a valve stern extending from saidvalve, afloat on the end thereo-Lafloat loosely fitted on said stem, and7 an adjustable stop 'With float cooperates. V 7 a o 8. 'A vacuum steamheating systemcomprisinga boiler,,radiators, steam supply and returnlines, a receiving and separating tank for-the condensate, a pumpingapparatus for placing thereturn side of the system under a vacuum, andsaidreturn line having a low ointlocated below the level of said tank, alift trap interposed "at substantially the low Which saidlast namedpoint in the return line, said lift trap having a valve for admittingair thereto, and a large float, a11da small float coacting to operatesaid valve. I

- 9V.v A vacuum prising a boiler, radiators, steam supply and returnlines, a receiving and separating tank 7 for the condensate, a pumpingapparatus for placing the return side of the system under a vacuum, andsaid return line having a low point'locatedbelow the level of said tank,a lift trap and a check valve opening towards v the trap interposed atsubstantially the low point in the returnline, said lift trap having avalvefor admitting airthereto, and float 'mechanism'for operatingv saidvalve.

-10. 'A vacuum steam heatingsystem, comprising a boiler, radiators,steam supply and return lines, a receiving and separating tank for thecondensate, a pumping apparatus for placing thereturn side of the systemunder a vacuum and returning the Water of condensation to theb'oiler,.said return line having a low point located below the level ofsaid tank,'and an automatically operating pumping 'mechanism interposedsubstantially at said low point in the return line forlfeeding fluidinto'said tank.

In testimony whereof I aflixed mysignaturer e 7 7 r DOUGLAS E. NASH. e

have hereunto ste'am heating system com-

